Implement frame tube joint with weldable connector

ABSTRACT

A tube over tube joint for an implement frame includes a self-fixturing weldable connector positioned between upper and lower tubes. Standard fillet welds connect the tubes to the connector. A unitary casting can be used made from material selected to optimize load transfer between the top and bottom tubes to improve the fatigue life of the joint. The casting is self-fixturing so the top tubes can be located by simply placing in the casting on the lower tubes. A tube end connector provides fixturing and weld surfaces for butt joints in planar frames. Outwardly extended weld edges on the connector increase resistance to parallelogramming.

FIELD OF THE INVENTION

The present invention relates generally to agricultural implement framesand, more specifically to tube joints for such frames.

BACKGROUND OF THE INVENTION

Many agricultural implement frames include tubular members welded orconnected together by brackets. The joints are subjected to very highloads and stresses.

Tube over tube connections for an implement frame construction typicallyemploy one of two methods of construction. The first method includeswelding the top and bottom tubes directly together using flare bevelwelds. The direct weld procedure requires joint welds in hard to reachpositions. If welds are required around tube corners, robotic weldingtechniques often are not used since programming the robot to closelyfollow the corners is not always possible. Fatigue and less than optimumload transfer characteristics of some joints can result in a weakenedframe. The second method of frame construction uses gusset platesvertically extending between the top and bottom tubes and welded to thetubes. The weld positioning is better using the gusset method than thedirect tube to tube weld method, but gusset weld methods often result ina joint with a lower fatigue life compared to other types of joints.

A further method involves tube through tube construction such as shownand described in commonly assigned U.S. Pat. No. 6,016,877. Suchconstruction provides excellent frame tube joints and a very strongoverall frame without need for extensive fixturing during manufacture,but such joints require laser cut apertures through tubes and arerelatively expensive to produce. In addition, welding tube ends toadjoining tubes in the same plane continues to be a source ofdifficulty.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an improved framejoint for an agricultural implement frame. It is another object toprovide such a joint that overcomes most or all of the aforementionedproblems.

It is a further object of the invention to provide an improved weldedframe joint for an implement which is stronger, subject to less fatigue,and easier to manufacture than at least most previously availableimplement frame joints. It is another object to provide such a jointwhich is self-fixturing and is easily weldable using standard filletwelds at conveniently accessed locations.

Tube over tube implement frame joints include self-fixturing weldablecastings positioned between upper and lower tubes. Standard fillet weldsconnect the tubes to the casting at conveniently accessible locations.The material in the casting is selected to optimize load transferbetween the top and bottom tubes to improve the fatigue life of thejoint. The weldable casting can be placed at any required joint area andprovides an easy weld joint for both human and robotic welders. Sincethe casting is self fixturing, the top tubes can be located by simplyplacing in the casting without need for costly fixtures. In anotherembodiment of the invention, castings are provided at the ends of tubesto facilitate butt joint fixturing and welding for connecting tubeslying in the same plane. The above-described connections spread the weldlocations for increased resistance to parallelogramming and better loadbalancing at the joints. The connections also provide added strength andfatigue resistance at tube joints adjacent hinge locations.

These and other objects, features and advantages of the presentinvention will become apparent from the description below taken in viewof the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a portion of an agricultural implementframe.

FIG. 2 is an enlarged perspective view of a frame joint for the frame ofFIG. 1.

FIG. 3 is a perspective view of a connector utilized with the framejoint of FIG. 2.

FIG. 4 is a perspective view of another embodiment of a connectorutilized for a tube over tube construction.

FIG. 5 is a perspective view of the connector of FIG. 4 welded to frametube.

FIG. 6 is a perspective view of a frame butt joint for connecting a tubeend to an adjoining tube in generally the same plane.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, therein is shown an implement frame 10 havingtransversely extending tubular beam or frame tubes 12, 14 and 16connected to fore-and-aft extending tubular beam or frame tubes 18, 20,22, 24 and 26. The beams are rectangular in cross-section with roundedcorners, and a beam over beam construction is utilized to connect thetubes 12, 14 and 16 to the beams 20, 22, 24 and 26 to provide a mainframe of generally rectangular configuration. The right ends (as viewedin FIG. 1) of the beams 12-16 are connected to the inside face of thefore-and-aft beam 18. For purposes of the description, the beams 20-26are designated as lower or first beams and the beams 12-16 aredesignated as upper or second beams, but it is to be understood that thepositions can be reversed or otherwise changed and that the upper andlower designations are for providing a reference for clarity in thedescription of the drawings. Earthworking or seeding tools and hitchstructure (not shown) for towing the frame forwardly (F) through a fieldwith the tools engaging the soil. The heavy loads encountered by theimplement frame 10 during transport and field-working operations requirestrong connections at the beam joints.

To provide self-fixturing and a strong, permanent connection between theupper and lower beams, a weldable connector or casting 30 is positionedat joint locations. The casting 30 as shown in FIGS. 2 and 3 includes anupwardly directed channel or saddle portion 32 (FIG. 3) and a downwardlyopening channel or saddle portion 34. For a right-angle joint as shownin the figures, the saddle portion 32 includes a channel 32 c conforminggenerally to the shape of the upper beam 16 (FIG. 2) and a channel 34 cconforming generally to the shape of the lower beam 20 and perpendicularto the channel 32 c. The connector 30 can be fixed to one of the beamsand functions as a fixture to locate the other of the beams. The channelconfigurations thus provide easy and reliable set up of the framecomponents without need for additional fixturing.

As best seen in FIGS. 2 and 3, the connector 30 includes opposite pairsof bifurcated flanged or leg portions 40 having generally planar insidesurfaces 44 defining the channel 34 c. Slots 46 with arc-shaped topportions 48 separate the leg portions 40, and tapered flanges 50 projectoutwardly from the channel 34 c. The leg portions 40 extend upwardly toa connection with bottom 32 b (FIG. 3) of the saddle portion 32. Thebottom 32 b is generally open between the opposite leg portions 40.

Planar channel walls 52 extend upwardly from the bottom 32 b to definethe channel portion 32 c. The walls 52 include uppermost edges 56 havinga height approximately half the dimension of the corresponding wall ofthe beam 16. A notch 58 is centrally located in each uppermost edge andprovides a paint drainage channel. The connector 30 is fixed to theupper beam 16 or first frame tube by welds at locations 60 between thecorners of the beam. The first frame tube is welded at the centrallocations to the uppermost edges so that the first frame tube issubstantially devoid of welds adjacent corners of the tube. The welds 60are offset from the corners for easy access, to reduce or eliminate thewelds at the beam corners, and to provide better load and stressdistribution at the joints. The leg portions 40 are welded to thecorresponding walls of the beam 20 at locations 62 also offset from thebeam corners.

In an alternate embodiment (FIGS. 4 and 5), a connector 70 includesopposite leg portions 80 which are generally planar and define thechannel 34 c of saddle portion 34′. The leg portions 80 extend upwardlyto a connection with bottom 82 b of saddle portion 32′. The bottom 82 bis open between the leg portions 80 and connects to planar channel sidewalls 92 having top edges 96 with a central raised edge portion 98. Aside extension 100 is located outwardly of each of the side walls 92 andprovides a conveniently located edge for connecting the extension to thetop surface of the tube 20 (FIG. 5) at weld location 102. The oppositeedges of the leg portions 80 are welded at 104 to the side walls of thetube 20. The welds 104 are offset from the tube corners. The edges 96are welded at locations 106 to the upright side walls of the tube 16.The extension 100 provides a central weld location relative to theadjoining beam 20 and provides good distribution of stress at the joint.By spreading out the weld locations with the connectors as shown,resistance to parallelogramming is increased and stresses on the tubesare reduced. The joint is thus strengthened, and problems of in-planeshearing caused by frame parallelogramming are reduced or eliminated.The raised portion 98 does not require welding and provides a locatorfor the innermost portions the welds 106.

To provide butt joints for a planar configuration (FIG. 6), a weldableconnector 132 includes a saddle portion 132 opening towards a first beamor tube 20′. The saddle portion 132 includes leg portions 140 similar inconstruction to the leg portions 40 described above for FIGS. 2 and 3and defining a channel 134 c for receipt on the tube 20′. A saddleportion 144 conforms to the cut end of a second tube 16′ and includesplanar channel walls 162 with curved edges 170 which are welded atlocations 172 to opposite walls of the tube 16′. The welds at 172 areoffset inwardly from the corners of the tube 16′. Welds 174 connect theleg portions 140 to the walls of the tube 20′ inwardly of the adjacentcorners of the tube. A hinge receiving end of the tube 20′ can receivehinge structure (not shown) for connecting one section of the implementframe to an adjoining section adjacent the connector 132. Theabove-described joint provides a strong and fatigue-resistant connectionat the hinge area.

Having described the preferred embodiment, it will become apparent thatvarious modifications can be made without departing from the scope ofthe invention as defined in the accompanying claims.

1. An agricultural implement frame comprising: a first frame tube of rectangular cross section; a second frame tube of rectangular cross section; the first and second frame tubes each having lengths and opposed side walls connected at corners by upper and lower walls; and a self-fixturing permanent connection located at a joint location between the first and second frame tubes, the permanent connection including a weldable connector insertible between the first and second frame tubes along the lengths of the tubes inwardly of ends of the tubes and having an upwardly directed channel with planar upright walls having uppermost edges terminating adjacent the first frame tube side walls adjacent central locations on the side walls of the first frame tube between the upper and lower walls of the first frame tube, wherein the planar upright walls contact and are parallel to the side walls of the first frame tube, the weldable connector including a downwardly open channel, the upwardly directed channel conforming generally to the shape of a lower portion of first frame tube, and the downwardly opening channel conforming generally to the shape of an upper portion of the second frame tube, wherein the connector functions as a fixture to locate the first and second frame tubes relative to each other during assembly, wherein the first frame tube is welded at the central locations to the uppermost edges and is substantially devoid of welds adjacent the corners for welding access and distribution of frame tube load and stress.
 2. The implement frame as set forth in claim 1 wherein the downwardly open channel includes opposite pairs of bifurcated leg portions having generally planar inside surfaces parallel to the side walls of the second tube and defining the downwardly open channel.
 3. The implement frame as set forth in claim 2 further including arc-shaped top portions separating the leg portions.
 4. The implement frame as set forth in claim 2 wherein the leg portions are flanged.
 5. The implement frame as set forth in claim 4 wherein the connector is open between the downwardly open channel and the upwardly directed channel between the opposite leg portions.
 6. The implement frame as set forth in claim 2 wherein the leg portions are welded to the side walls of the second frame tube at locations offset from the corners of the side walls of the second frame tube.
 7. The implement frame as set forth in claim 1 wherein each of the uppermost edges is welded at two offset locations to the first frame tube.
 8. The implement frame as set forth in claim 7 including a paint drainage notch centrally located between the offset locations of each uppermost edge and separating the two offset locations.
 9. The implement frame as set forth in claim 1 wherein the first frame tube is perpendicular to the second frame tube. 